Previously, many types of twist tying machines and apparatus have been used in endeavoring to provide an effective means to close the open end of an outer covering over an article such as bread wrappers, produce products etc.
A search of the prior art did not disclose any patents that possess the novelty of the instant invention; however the following U.S. patents are considered related:
Pat. NumberInventorIssue Date3,898,924Mead et al.Aug. 12, 19754,177,842DilleyDec. 11, 19794,117,988MooreOct. 3, 19784,559,977DilleyDec. 24, 19855,389,190Larsen et al.Feb. 14, 19955,613,530Contreras et al.Mar. 25, 19975,836,137Contreras et al.Nov. 17, 1998
Mead et al. in U.S. Pat. No. 3,898,924 teaches an operable hoop shaped tape guide, a first clamp that holds the tape while the slack is taken up and a second clamp holding the tape until it is severed and twisted. The improvement is a rotatably mounted cam which pushes against cam followers on push members and operates clamps as a knife. A series of lobes formed in the surface of the cam displace the push members and fix the time relationship and sequence of the events.
U.S. Pat. No. 4,177,842 issued to Dilley is for improved clamps having clamping strokes of a prescribed dimension actuated by air pressure, such that the strokes are terminated only when the clamping rods actually abut. Thus wear or looseness does not adversely affect function of the clamping rods.
Moore in U.S. Pat. No. 4,117,988 discloses an adapter having a tubular center section and a pair of circular flange sections at each end of the tubular center section. One of the flanges is movable to insert or release the tie tape. The tube is segmented circumferentially and expands to engage the coil of tie tape.
Dilley in U.S. Pat. No. 4,559,977 teaches tie material encircling produce fed by pressure rollers forming a complete loop. A first gripper clamps the material between a second gripper. The pressure rollers reverse retracting excess material. A friction clutch allows slippage when tightening. A twister head rotates the material and shearing edges sever the material. Rack and pinion mechanisms rotate the twister head and forward and reverse feeding.
U.S. Pat. No. 5,389,190 issued to Larsen et al. is for an extracting and cutting mechanism with a magnetic application mechanism producing a magnetic force to remove the twist-tie from the extracting and cutting mechanism. A dispensing mechanism dispenses hot melt tape on the twist-tie held by the magnetic application mechanism then applies the twist-tie to a surface of a container.
Contreras et al. in U.S. Pat. No. 5,836,137 discloses a pneumatic drive apparatus having a rotary actuator with a gear and one-way clutch. A control valve energizes the rotation direction and a roller limit valve energizes the control valve to complete the functional operation of encircling, gathering, twisting and cutting tie tape around an article. A pneumatic valve bypasses the manual trigger system in the event of malfunction or jam allowing the device to reset itself into the ready to operate position.
For background purposes and as indicative of the art to which the invention is related reference may be made to the remaining cited U.S. Pat. No. 5,613,530 issued to Contreras et al.